The overall of this project is the enhancement of the capabilities of positron emission tomography (PET) imaging of the heart by improving the quantitative and qualitative analysis of PET image data. Corrections currently employed in quantitative studies do not adequately consider the partial volume and aliasing effects arising form axial undersampling. Improved three-dimensional display methods are required as PET moves in to the clinical arena. The specific goals of this project are: 1) A quantitative study of artifacts arising form undersampling and cardiac motion; 2) Development of improved three-dimensional display methods; 3) Development of physiological images of myocardial blood flow and oxygen utilization; 4) Incorporation of an image computer with the new display methods. To achieve the first goal, the primary focus will be an analysis of artifacts induced by sampling undersampling in the axial direction. Simulation and phantom studies will be performed and patient data will be analyzed. The magnitude of the artifacts in 7-slice tomographs will be assessed, then the analysis will incorporate noise effects to determine if there is an optimal number of slices. Finally, the effects of cardiac and respiratory motion will be evaluated in terms of the partial volume effect. New volume and surface-rendering methods to artifact generation. Digital filters will be applied to blood-pool and myocardial images. Images of myocardial blood flow and oxygen utilization will be generated using models under development at Washington University that relate these physiologically important measures to the collected image data. An image computer, consisting of video display system tightly coupled to an array processor, will be used to provide interactive rotation of three- dimensional images and interactive adjustment of critical display parameters.